Means for preventing occlusion of hydrogen in metal cathodes



.Patented Mar. 4, 1924. 0.

UNITED STAT-ES 1,485,436 PATENT OFFICE.

JOSEPH SLEPIAN, OF WILKINSBUBG, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSEELECTRIC dc MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

MEANS FOR PREVENTING OCCLUSION OF HYDROGEN IN METAL CATHODES.

No Drawing.

To all whom it may comm:

Be it known that I, Josnrn SLEPIAN, a citizen of the United States, anda resident of Wilkinsbur in the oounty'of Allegheny and State ofennsylvania, have invented a new and useful Improvement in Means forPreventing Occlusion of Hydrogen in Metal Cathodes, of which thefollowing is a specification.

My invention relates to electrolytic reactions and methods of conductingthem, and it has, for its primary object, the provision of a method bywhich the occlusion of gases, and, particularly, of hydrogen in metallicelectrodes, to any material extent is prevented.

Heretofore, for some purposes, considerable difliculty has beenexperienced in electro-plating steel and other ferrous metals because ofthe deleterious effect upon such metals occasioned by occluded gasesand,

particularly, hydrogen which may have been absorbed by them during theelectro-plating treatment. The primary object of my present invention,therefore, resides in the provision of a method of electro-platingferrous bodies or articles in such manner as to prevent, to as great anextent as possible, any occlusion of gases in the metals being treated.

I have observed that, when employing metallic electrodes in a suitableelectrolyte, in the nature of a cold solution, even very small currentswould produce gas at the electrodes, and the electrolyte, on thisaccount, would oifer an abnormal resistance to the passage of current.As the solution warmed up, however, I noted that the gases disappearedand that. between the temperature 0' between 30 and 35 (3., the gassingceased and the resistance became normal, even for relatively highcurrent densities.

In my openion, this may be accounted for by assuming that, when hydrogenis liberated, in gaseous form, from a solution, by an electric current,it cannot be returned into solution by reversals of the current, becausethe gas thus liberated is a non-conductor. If, however, the hydrogenions are occluded by the metallic electrodes employed, they then actlike conducting varieties of hydrogen and will return into the solutionor electrolyte upon reversal of the current.

If the foregoing theory is correct, and all tests conducted by meindicate that it is, it

Application filed January 12, 1920. Serial No. 851,005.

will'be clear that gas occlusion in metallic electrodes, and,particularly, in ferrous elec' trodes, such as steel, increases rapidlywith the temperature of the electrolyte and especiall(y: when suchtemperature approaches 30 My present invention, therefore, resides inconducting electrolytic reactions of this character under suchconditions as to maintain theelectrolyte employed in a cool condition,in order that the ferrous electrodes being treated may not absorb thehydrogen or the other gases which may be given off. For example, inpractising my invention, I may dispose ferrous or steel electrodes in aproper electro-plating bath or electrolyte and I may pass a sultablecurrent between the electrodes through the bath while maintaining thebath in a cool state by any suit able means, as by the employment ofcooling coils immersed in the bath. Although I do not wish to berestricted to specific details, the primary feature of my inventionresides in keepin the temperature of the bath below 30 and, preferably,in keeping the bath relatively 0001.

In practising my invention, I may provide a solution of approximately 1%sodium car bonate in water and utilize electrodes of ingot iron ofsuitable The electrolysis may becarried out with a current density of to10 amperes per square inch at 25 cycles A. C. The temperature ispreferably maintained below 30 C.

While it is not essential, I prefer to practice my invention under areduced pressure, as this is also beneficial in keeping the gases fromgoing into the metallic electrodes. In view of the relatively broadscope of my invention, including, as it does, the employment of numerouscharacters of electrodes and electrolytic solutions, it will beapprecia-ted that no limitations are to be imposed upon my inventionother than those indicated in the appended claims.

I claim as my invention 1. The method of preventing occlusion of gasesin ferrous electrodes ofelectrolytic apparatus that comprisesmaintaining the electrolyte employed in a cool state.

2. The method of preventing occlusion of gases in iron being treatedduring electroplating that comprises keeping the electrolytic bath at atemperature below 30 C.

3. The method of preventing occlusion of gases in iron being treatedduring electroplating that comprises keeping the electrolytic bath at atemperature below 30 (3., and carrying out the operation under sublsatmospheric ressure.

4. The met 0d of preventing occlusion of gases in ferrous electrodes ofelectrolytic apmsewwe paratus that comprises maintaining the electrolyteemployed in a cool state and electrolyzing with an alternating current.

In testimony whereof, I have hereunto subscribed my name this 31st dayof Decemher 1919. V

JOSEPH SLEPIAN.

